All I have are large pistol primers, and I'm pretty new to reloading, so I've been reloading alot of .45 Colt. I shoot them through a .454 though, so in case I make a rookie mistake, I have about 40,000 PSI of wiggle room. I generally load to max or +P pressures, and with all sorts of 230-250 gr boolits, I've had nothing but success, until last weekend. It's my understanding that any safe load for a 250gr jacketed boolit will also be safe for a 185gr jacketed boolit, so I loaded up 17.5gr of 2400 behind a 185gr .4515 HP. I have no roll crimp die yet, so I used a 1/4 turn with my taper crimp die, and watched for boolits coming out of the cases. I didn't see any evidence of that, but I did have some moderately flattened primers on about 1/2 of my loads. My theory after thinking it over at work is that the light, slightly undersized boolit combined with the non-ideal crimp allowed the primer to push the bullet forward slightly before the 2400 burned right (it's a magnum pistol, slow burning powder) and created a secondary pressure spike that mooshed up my primers a bit. Recoil and noise varied quite a bit shot to shot, like shooting .22LR on a very cold day. Recoil was never stout, even by .45 Colt standards (4.5# gun as well) but I could definately feel a difference. Does my theory make sense, or did I just make it up in my head?

I took her out again today, this time with the cases loaded up with Unique, and had a much better time. I still need a roll crimp die, my 5th and 6th boolits are backing out a hair from recoil, but nothing scary. I did start to flatten some primers at the end, but not until I was running those 185 HPs at about 1300 FPS. My next question: Are regular large pistol primers designed for that type of pressure, or should I be running LP magnum primers as I chase 1400 FPS?

Picked up Lee's factory crimp die and a Chrony. Those 185s are actually running 1385fps average, but #5 and 6 in the cylinder are still backing out under recoil. I've also been running 230gr Berry's plated at about 1205fps with the same 1/2 turn crimp, and they don't move a bit, awesome plinking round and very accurate. What I'd really like to find are some flying ashtray 185s that are .452" instead of .4515" to maybe get just a little snugger crimp. Until then, I'm putting development on hold, and concentrating more on the FsN for HD